Drive unit for a music box

ABSTRACT

A music box includes interconnected cover parts which define a hollow case for housing a drive unit, the drive unit includes a gear transmission system having shafts with gears fixedly mounted thereon in meshing relationship. A plurality of slots are provided in one cover part for supporting the shafts and the other cover part has a plurality of complementary projections which extend into the slots for maintaining the shafts in alignment. The one cover part is mounted on a support plate and all the shafts of the gear transmission system are arranged in planes parallel to the plane of the support plate to facilitate assembly of the music box.

United States Patent Matthey [4 1 Aug. 22,1972

54] DRIVE UNIT FOR A MUSIC BOX 72 Inventor: Emile Charles Matthey, CH 1445 Prim? Wilkins Vuiteboeuf, Buiteboeuf, Switzerland Assistant Examiner-Lawrence R. Franklin Att0rney-Robert E. Burns and Emmanuel J. Lobato [22] Filed: Sept. 29, 1970 [21] Appl. No.: 76,441 ABSTRACT R l t A r A music box includes interconnected cover parts ea ed S pp canon Data which define a hollow case for housing a drive unit, COnImuatwn-m-part 0f the drive unit includes a gear transmission system hav- 1963, abandoneding shafts with gears fixedly mounted thereon in mesh- L ing relationship. A plurality of slots are provided in U-S. one cover part f Supporting th h ft d th th [51] Int. Cl. ..GlOf 1/06 cover part has a plurality of complementary projec [58] Fleld 0f stalch ..84/94-96 tions which extend into the Slots for maintaining the shafts in alignment. The one cover part is'mounted on [56] References C'ted a support plate and all the shafts of the gear transmis- UNITED STATES PATENTS sion system are arranged in planes parallel to the 526 499 9/1894 Pamard et a1 84/95 plane of the support plate to facilitate assembly of the music 2,836,260 5/1958 Nozawa ..84/95 3,390,599 7/1968 Komatsu ..84/96 5 Claims, 4 Drawing Figures f8 f5 28 l4 1 DRIVE UNIT FOR A MUSIC BOX BACKGROUND OF THE INVENTION This application is a continuation-in-part application of my application, Ser. No. 768,783 filed on Oct. 18, 1968, and now abandoned.

This invention relates to music boxes and in particular to music boxes in which a drive unit for the music box is housed in a case separate from the rotary drum which is provided with pins for engaging the reeds of a reed plate to vibrate the reeds and produce musical sounds.

It is known to provide a music box having a case formed by two cover parts. In one part are formed flanges and projections for supporting the spindles or axles of the gears forming part of the transmission mechanism of the music box. Complementary grooves are formed in a flanged edge of the other part which cooperate with the flanges and projections of the one part to maintain the spindles of the gears in proper alignment. During assembly of the music box, the spindles of the gears can roll freely along the upper surfaces of the flanges and projections thereby necessitating a the careful adjustment of said spindles before the cover parts are finally fixed together to ensure correct alignment of the spindles and meshing of the gears. Such a careful adjustment is time consuming and requires a certain dexterity on the part of the assembler.

Further, in such known music boxes, the spindle carrying a governor is mounted such that it lies in a plane at right-angles to the planes containing the longitudinal axes of the remaining spindles. This arrangement can lead to difficulties when assembling the transmission mechanism within the case.

Also, in such known music boxes, the drive output shaft from the transmission mechanism is so arranged with respect to the rotary drum which carries the pins for engaging the reeds of a reed plate that a gear has to be provided on the drive output shaft for meshing with a gear on the rotary drum, for rotating said drum. A portion of the gear on the drive output shaft extends outwardly through a slot in the case and the slot forms an access path for the ingress of dirt and foreign matter into the case. The dirt and foreign matter can seriously damage and effect the performance and the life of the transmission mechanism.

AIMS OF THE INVENTION An object of the present invention is to provide a music box which is easy to assemble and which thereby cuts down the assembly time and cost of the music box.

A further object of the present invention is to provide a music box having a gear transmission system which is substantially enclosed thereby protecting the system from dirt and foreign matter.

According to the present invention, a music box comprises two interconnected cover parts each having one open side and which together define a hollow case. A drive unit housed within the hollow case is and includes a gear transmission system having shafts with gears fixedly mounted thereon in meshing relationship. A plurality of slots are arranged at predetermined positions in one cover part, each slot supporting an end portion of a shaft, and a plurality of complementary projections are arranged on the other cover part, each projection extending into a slot and cooperating therewith to maintain the shaft end portions in alignment. A support plate is provided and the one cover part is attached to the support plate on its side opposite the one open side. All the shafts of the gear transmission system are arranged in planes parallel to the plane of the support plate for facilitating and simplifying assembly.

Preferably, the hollow case and the support plate define a substantially sealed chamber for the drive unit.

Preferably, an output shaft from the gear transmission system is supported by and extends through a through slot in a side of the one cover part and the portion of the output shaft extending from said side has a square configuration.

The one cover part may include an inner wall having slots for supporting one end portion of some of the shafts.

Preferably, the gear transmission system is made of a synthetic plastics material.

DESCRIPTION OF THE DRAWINGS An embodiment of the invention will now be described, by way of example, reference being made to the figures of the accompanying drawing in which:

FIG. 1 is a plan view of a hollow case containing a gear transmission system of a music box, one cover part of the case being removed;

FIG. 2 is a diagrammatic sketch partly in cross-section of the case of FIG. I mounted on a support plate;

FIG. 3 is a plan view of the other cover part of the case; and

FIG. 4 is a diagrammatic view partly in section of the said other cover part of FIG. 3.

DESCRIPTION OF A PREFERRED EMBODIMENT As shown in the drawings, a drive unit for driving a rotary drum (not shown) of a music box is housed within a case comprising two cover parts 100, 101, made of moulded synthetic plastics material.

The cover part is formed with an inner wall 10 which defines with the outer wall of the cover part 100, two chambers, a chamber 9 for receiving a spring motor (not shown) of the drive unit and a chamber 11 in which is arranged a cylinder gear 2 driven by the spring motor.

The cylinder gear 2 forms part of a gear transmission system mounted in the cover part 100 which includes a gear wheel 3 rigidly connected to a pinion 4 which meshes with the cylinder gear 2, a gear wheel 5 rigidly connected to a pinion 6 which meshes with a gear wheel 3, and a governor 7 including a worm screw 8 which meshes with the gear wheel 5.

The gear wheels and pinions are mounted on shafts which are supported in slots made in the inner wall 10 and outer wall of the cover part 100. The shaft supporting the cylinder gear'2 is supported by slots l2, 13. The shaft supporting the gear wheel 5 and pinion 6 is supported by slots 16, 17. The shaft supporting the governor 7 is supported by slots l8, 19.

The cover part 100 is mounted on a support plate 102. The shafts of the gear transmission system are arranged in planes parallel to the plane containing the support plate 102.

The slot 12 is a through slot to enable the passage through the outer wall of the cover part 100 of the outer extremity of the shaft of the cylinder gear 2. The extremity 20 is substantially square to enable the simple but effective coupling to the shaft of a selected one of a plurality of rotary drums. This enables the tune of the music box to be varied in a very quick and easy manner.

The remaining slots are made in only part of the thickness of the walls so that the shafts are protected inside the cover part 100 and are maintained axially as well as radially.

The radial retention of the shafts in the slots is ensured by the cover part 101 which is provided with projections 21, 22, 23, 24, 25, 26 and 27 each complementary to a slot. The projections partially extend into the slots 12 to 19 of the cover part 100. The cover parts 100, 101 are secured together to define the case by screws (not shown) which pass through the holes 28 in the cover parts.

The gear transmission system is quickly and accurately assembled by introducing the ends of each shaft into the appropriate slots in the cover part 100 and then positioning the cover part 101 so that the projections partially enter into the slots to thereby position and maintain the shafts in correct alignment. Assembly is facilitated since the shafts are each in a plane parallel to the plane of the support plate and can be positioned above the slots in the cover part 100 and then dropped or rolled into the slots which can have a slight lead in or flare, the shafts thereby automatically placing themselves in correct alignment by virtue of their own weight. The gear transmission system is preferably made of a synthetic plastics material such as nylon sold under the trademark of DELRIN. The making of most of the parts of the music box in a synthetic plastics material, makes possible an inexpensive and large scale production and considerably reduces the weight of the music box.

The cover parts 100, 101 together with the support plate 102 define a substantially sealed chamber effectively protecting the drive unit from foreign matter. The only access into the sealed chamber is along the shaft 12 and through its associated through slot. However, this can be sealed by any known means.

What is claimed is:

1. In a music box: two interconnected cover parts each having one open side and which together define a hollow case, a drive unit housed with the hollow case, the drive unit including a gear transmission system having shafts with gears fixedly mounted thereon in meshing relationship, means defining a plurality of slots arranged at predetermined positions in one cover part, each slot supporting an end portion of one of said shafts, a plurality of complementary projections on the other cover part, each projection extending into a slot and cooperating therewith to maintain the shaft end portions in alignment, a support plate attached to said one cover part at its side opposite the one open side, and means positioning all the shafts of the gear transmission system in planes parallel to the plane of the support plate for facilitating assembly of the music box.

2. In a music box according to claim 1, wherein the hollow case and the support plate define a substantially sealed chamber for the drive unit.

3. In a music box according to claim 1, wherein said ear transmissions t m include an ut ut sh u r iorted by and ext r id ing througl 'i a thro iigh sib i in a side of said one cover part, and wherein said output shaft has an end portion extending from said side and having a square configuration.

4. In a music box according to claim 1, wherein said one cover part includes an inner wall having slots therein for supporting one end portion of some of said shafts.

5. In a music box according to claim 1, wherein the gear transmission system is made of synthetic plastics material. 

1. In a music box: two interconnected cover parts each having one open side and which together define a hollow case, a drive unit housed with the hollow case, the drive unit including a gear transmission system having shafts with gears fixedly mounted thereon in meshing relationship, means defining a plurality of slots arranged at predetermined positions in one cover part, each slot supporting an end portion of one of said shafts, a plurality of complementary projections on the other cover part, each projection extending into a slot and cooperating therewith to maintain the shaft end portions in alignment, a support plate attached to said one cover part at its side opposite the one open side, and means positioning all the shafts of the gear transmission system in planes parallel to the plane of the support plate for facilitating assembly of the music box.
 2. In a music box according to claim 1, wherein the hollow case and the support plate define a substantially sealed chamber for the drive unit.
 3. In a music box according to claim 1, wherein said gear transmission system includes an output shaft supported by and extending through a through slot in a side of said one cover part, and wherein said output shaft has an end portion extending from said side and having a square configuration.
 4. In a music box according to claim 1, wherein said one cover part includes an inner wall having slots therein for supporting one end portion of some of said shafts.
 5. In a music box according to claim 1, wherein the gear transmission system is made of synthetic plastics material. 